This invention relates primarily to apparatus especially useful in the controlling of continuously operating processing machinery such as equipment for blanching or roasting of peanuts, french fried potatoes, or for peeling potatoes and the like. In such controlled processes, the color of the product is detected as it leaves the processing area. Since the color changes with the degree of processing such as heating, blanching, peeling and the like, detection of the product color can be relied upon to indicate whether the procedure is satisfactory. Thereafter, the timing or temperature usually can be altered to optimize the process. Past color detectors have included a light emitting head which is stationary over the product. The product is carried by a conveyor through a heating oven or the like and thereafter beneath the head of the color detector. Because the product is heated and in the process of being cooked it gives off various gases and radiates heat. If the color detecting head is exposed to an overtemperature condition or if vapor carried matter collects on the lens it can be rendered inoperative.
Because the product is stacked on a conveyor for movement through a heating processor, the distance between the head and the product can vary due to changes in the depth of the product on the conveyor. This variance in spacing between the head and the product, as well as the degree to which the conveyor is covered by the product, can change significantly the detected color. Thus, in the case of the processor being controlled by a signal responsive to this color, erroneous control signals are generated.
It is the purpose of the present invention to provide an improved device for reading the color of a product.